Halogenation Processes

ABSTRACT

The invention discloses improved processes to halogenate polymers. In particular, the invention discloses to improved processes to halogenate polymers made from C 4 -10 12  isoolefins.

FIELD OF INVENTION

The invention relates to improved processes to halogenate polymers. Inparticular, the invention relates to improved processes to halogenatepolymers made from C₄-10₁₂ isoolefins.

BACKGROUND

Isoolefin polymers are prepared in carbocationic polymerizationprocesses. The carbocationic polymerization of isobutylene and itscopolymerization with comonomers like isoprene is mechanisticallycomplex. The catalyst system is typically composed of two components: aninitiator and a Lewis acid. Examples of Lewis acids include AlCl₃ andBF₃. Examples of initiators include Brönsted acids such as HCl, RCOOH(wherein R is an alkyl group), and H₂O. During the polymerizationprocess, in what is generally referred to as the initiation step,isobutylene reacts with the Lewis acid/initiator pair to produce acarbenium ion. Following, additional monomer units add to the formedcarbenium ion in what is generally called the propagation step. Thesesteps typically take place in a diluent or solvent. Temperature, diluentpolarity, and counterions affect the chemistry of propagation. Of these,the diluent is typically considered important.

Industry has generally accepted widespread use of a slurrypolymerization process (to produce butyl rubber, polyisobutylene, etc.)in the diluent methyl chloride. Typically, the polymerization processextensively uses methyl chloride at low temperatures, generally lowerthan −90° C., as the diluent for the reaction mixture. Methyl chlorideis employed for a variety of reasons, including that it dissolves themonomers and aluminum chloride catalyst but not the polymer product.Methyl chloride also has suitable freezing and boiling points to permit,respectively, low temperature polymerization and effective separationfrom the polymer and unreacted monomers. The slurry polymerizationprocess in methyl chloride offers a number of additional advantages inthat a polymer concentration of approximately 26% to 37% by volume inthe reaction mixture can be achieved, as opposed to the concentration ofonly about 8% to 12% in solution polymerization. An acceptablerelatively low viscosity of the polymerization mass is obtained enablingthe heat of polymerization to be removed more effectively by surfaceheat exchange. Slurry polymerization processes in methyl chloride areused in the production of high molecular weight polyisobutylene andisobutylene-isoprene butyl rubber polymers. Likewise polymerizations ofisobutylene and para-methylstyrene are also conducted using methylchloride. Similarly, star-branched butyl rubber is also produced usingmethyl chloride.

However, there are a number of problems associated with thepolymerization in methyl chloride, for example, the tendency of thepolymer particles in the reactor to agglomerate with each other and tocollect on the reactor wall, heat transfer surfaces, impeller(s), andthe agitator(s)/pump(s). The rate of agglomeration increases rapidly asreaction temperature rises. Agglomerated particles tend to adhere to andgrow and plate-out on all surfaces they contact, such as reactordischarge lines, as well as any heat transfer equipment being used toremove the exothermic heat of polymerization, which is critical sincelow temperature reaction conditions must be maintained.

The commercial reactors typically used to make these rubbers are wellmixed vessels of greater than 10 to 30 liters in volume with a highcirculation rate provided by a pump impeller. The polymerization and thepump both generate heat and, in order to keep the slurry cold, thereaction system needs to have the ability to remove the heat. An exampleof such a continuous flow stirred tank reactor (“CFSTR”) is found inU.S. Pat. No. 5,417,930, incorporated by reference, hereinafter referredto in general as a “reactor” or “butyl reactor”. In these reactors,slurry is circulated through tubes of a heat exchanger by a pump, whileboiling ethylene on the shell side provides cooling, the slurrytemperature being determined by the boiling ethylene temperature, therequired heat flux and the overall resistance to heat transfer. On theslurry side, the heat exchanger surfaces progressively accumulatepolymer, inhibiting heat transfer, which would tend to cause the slurrytemperature to rise. This often limits the practical slurryconcentration that can be used in most reactors from 26 to 37 volume %relative to the total volume of the slurry, diluent, and unreactedmonomers. The subject of polymer accumulation has been addressed inseveral patents (such as U.S. Pat. No. 2,534,698, U.S. Pat. No.2,548,415, U.S. Pat. No. 2,644,809). However, these patents haveunsatisfactorily addressed the myriad of problems associated withpolymer particle agglomeration for implementing a desired commercialprocess.

U.S. Pat. No. 2,534,698 discloses, inter alia, a polymerization processcomprising the steps in combination of dispersing a mixture ofisobutylene and a polyolefin having 4 to 14 carbon atoms per molecule,into a body of a fluorine substituted aliphatic hydrocarbon containingmaterial without substantial solution therein, in the proportion of fromone-half part to 10 parts of fluorine substituted aliphatic hydrocarbonhaving from one to five carbon atoms per molecule which is liquid at thepolymerization temperature and polymerizing the dispersed mixture ofisobutylene and polyolefin having four to fourteen carbon atoms permolecule at temperatures between −20° C. and −164° C. by the applicationthereto a Friedel-Crafts catalyst. However, '698 teaches that thesuitable fluorocarbons would result in a biphasic system with themonomer, comonomer and catalyst being substantially insoluble in thefluorocarbon making their use difficult and unsatisfactory.

U.S. Pat. No. 2,548,415 discloses, inter alia, a continuouspolymerization process for the preparation of a copolymer, the stepscomprising continuously delivering to a polymerization reactors a streamconsisting of a major proportion of isobutylene and a minor proportionisoprene; diluting the mixture with from ½ volume to 10 volumes ofethylidene difluoride; copolymerizing the mixture of isobutyleneisoprene by the continuous addition to the reaction mixture of a liquidstream of previously prepared polymerization catalyst consisting ofboron trifluoride in solution in ethylidene difluoride, maintaining thetemperature between −40° C. and −103° C. throughout the entirecopolymerization reaction . . . '415 teaches the use of borontrifluoride and its complexes as the Lewis acid catalyst and1,1-difluoroethane as a preferred combination. This combination providesa system in which the catalyst, monomer and comonomer are all solubleand yet still affords a high degree of polymer insolubility to capturethe benefits of reduced reactor fouling. However, boron trifluoride isnot a preferred commercial catalyst for butyl polymers for a variety ofreasons.

U.S. Pat. No. 2,644,809 teaches, inter alia, a polymerization processcomprising the steps in combination of mixing together a majorproportion of a monoolefin having 4 to 8, inclusive, carbon atoms permolecule, with a minor proportion of a multiolefin having from 4 to 14,inclusive, carbon atoms per molecule, and polymerizing the resultingmixture with a dissolved Friedel-Crafts catalyst, in the presence offrom 1 to 10 volumes (computed upon the mixed olefins) of a liquidselected from the group consisting of dichlorodifluoromethane,dichloromethane, trichloromonofluormethane, dichloromonofluormethane,dichlorotetrafluorethane, and mixtures thereof, the monoolefin andmultiolefin being dissolved in said liquid, and carrying out thepolymerization at a temperature between −20° C. and the freezing pointof the liquid. '809 discloses the utility of chlorofluorocarbons atmaintaining ideal slurry characteristics and minimizing reactor fouling,but teaches the incorporation of diolefin (i.e. isoprene) by theaddition of chlorofluorocarbons (CFC). CFC's are known to beozone-depleting chemicals. Governmental regulations, however, tightlycontrols the manufacture and distribution of CFC's making thesematerials unattractive for commercial operation.

Additionally, Thaler, W. A., Buckley, Sr., D. J., High Molecular-Weight,High Unsaturation Copolymers of Isobutylene and Conjugated Dienes, 49(4)Rubber Chemical Technology, 960 (1976), discloses, inter alia, thecationic slurry polymerization of copolymers of isobutylene withisoprene (butyl rubber) and with cyclopentadiene in heptane.

Therefore, finding alternative diluents or blends of diluents to createnew polymerization systems that would reduce particle agglomerationand/or reduce the amount of chlorinated hydrocarbons such as methylchloride is desirable.

Hydrofluorocarbons (HFCs) are of interest and the use of HFCs inpolymerization processes has been disclosed in, for example, WO2004/058828 and WO 2004/058827. However, the use of HFCs inpolymerization processes would require finding new post-polymerizationor “downstream” processes that would accommodate for such newtechnology.

Among such post-polymerization or “downstream” processes are processesfor halogenation of the polymer. For example, U.S. Pat. No. 5,883,198discloses, inter alia, an improved process for the bromination of aC₄-C₆ isoolefin-C₄-C₆ conjugated diolefin polymer which comprisespreparing a solution of said polymer in a solvent, adding to saidsolution bromine and reacting said bromine with said polymer at atemperature of from about 10° C. to about 60° C. and separating thebrominated isoolefin-conjugated diolefin polymer, the amount of brominebeing from about 0.30 to about 1.0 moles per mole of conjugated diolefinin said polymer, the improvement being that said solvent is a mixturecomprising an inert saturated paraffinic hydrocarbon and an inerthalogen-containing hydrocarbon in a volume ratio of from about 90/10 toabout 10/90 of said paraffinic hydrocarbon to said halogen-containinghydrocarbon, wherein said halogen-containing hydrocarbon is a mono-, di-or tri-halogenated C₁ to C₆ paraffinic hydrocarbon or a halogenatedaromatic hydrocarbon. Preferably, the halogen-containing hydrocarbon isselected from the group consisting of methyl chloride, methylenechloride, ethyl chloride, ethyl bromide, dichloroethane, n-butylchloride and monochlorobenzene. See, also, U.S. Pat. Nos. 6,204,338,6,262,409, EP 0 803 517 B1, and EP 0 803 518 B1.

However, finding new halogenation processes that would easily lendthemselves to the use of HFCs and/or improve the efficiency of thehalogenation process would be desirable.

SUMMARY OF THE INVENTION

In an embodiment, the invention provides for a process to halogenate apolymer, the process comprising contacting at least one polymer havingC₄-C₁₀ isoolefin derived units, at least one halogen, and at least onehydrofluorocarbon in a solution to produce at least one halogenatedpolymer.

In yet another embodiment, the invention provides for a process tohalogenate a polymer, the process comprising contacting at least onehalogen and at least one polymer having C₄-C₁₀ isoolefin derived unitsproduced from a slurry polymerization process utilizing one or morehydrofluorocarbons in a solution to produce at least one halogenatedpolymer.

In any of the previous embodiments, the solution may contain anon-functionalized hydrocarbon solvent.

DETAILED DESCRIPTION

Various specific embodiments, versions and examples of the inventionwill now be described, including preferred embodiments and definitionsthat are adopted herein for purposes of understanding the claimedinvention. For determining infringement, the scope of the “invention”will refer to any one or more of the appended claims, including theirequivalents, and elements or limitations that are equivalent to thosethat are recited.

As used herein, the new numbering scheme for the Periodic Table Groupsare used as in CHEMICAL AND ENGINEERNG NEWS, 63(5), 27 (1985).

A reactor is any container(s) in which a chemical reaction occurs.

Slurry refers to the mixture of diluent comprising polymers that haveprecipitated from the diluent, unreacted monomers, and a catalyst systemand/or catalyst system components. The slurry concentration is theweight percent of the partially or completely precipitated polymersbased on the total weight of the slurry.

Solution refers to any mixture of at least one solvent and at least onepolymer, wherein the solvent or a solvent mixture is able to dissolvethe polymer to produce a single-phase homogenous mixture.

Polymer may be used to refer to homopolymers, copolymers, interpolymers,terpolymers, etc. Likewise, a copolymer may refer to a polymercomprising at least two monomers, optionally with other monomers.

When a polymer is referred to as comprising a monomer, the monomer ispresent in the polymer in the polymerized form of the monomer or in thederivative form of the monomer. Likewise, when catalyst components aredescribed as comprising neutral stable forms of the components, it iswell understood by one skilled in the art, that the ionic form of thecomponent is the form that reacts with the monomers to produce polymers.

Isobutylene-based polymer refers to polymers comprising at least 80 mol% repeat units from isobutylene.

Isoolefin refers to any olefin monomer having two substitutions on thesame carbon.

Multiolefin refers to any monomer having two or more double bonds. In apreferred embodiment, the multiolefin is any monomer comprising twoconjugated double bonds such as isoprene.

Elastomer or elastomeric composition, as used herein, refers to anypolymer or composition of polymers consistent with the ASTM D1566definition. The terms may be used interchangeably with the term“rubber(s)”, as used herein.

Alkyl refers to a paraffinic hydrocarbon group which may be derived froman alkane by dropping one or more hydrogens from the formula, such as,for example, a methyl group (CH₃), or an ethyl group (CH₃CH₂), etc.

Aryl refers to a hydrocarbon group that forms a ring structurecharacteristic of aromatic compounds such as, for example, benzene,naphthalene, phenanthrene, anthracene, etc., and typically possessalternate double bonding (“unsaturation”) within its structure. An arylgroup is thus a group derived from an aromatic compound by dropping oneor more hydrogens from the formula such as, for example, phenyl, orC₆H₅.

Halogenation refers to reactions between at least one polymer containingat least one unsaturation unit contacted with at least one halogen toincorporate the at least one halogen into the polymer to form ahalogenated polymer. The reactions typically proceed, for example,either in solution or in bulk. The halogenated polymer can containvarious levels of incorporated halogen atoms on the polymer backbonedepending on the degree of unsaturation of the starting polymer and theamount of halogen used. For example, the unsaturation unit may be adiene unit such as isoprene. Other polymers may be halogenated requiringsome type of treatment, e.g., either chemical or process related, priorto halogenation such as polymers containing alkylstyrene units, such aspara-methylstyrene. For example, these polymers may be halogenated usingheat, light, and/or free radical initiators or sensitizers, such asorganic peroxides or bis azo compounds, discussed in more detail below.Additionally, the at least one halogen may be, for example, bromine,chlorine, or both.

Halogen utilization refers to the relative amount of halogenincorporated into the polymer backbone and the amount of halogen usedfor the halogenation reaction. As is well understood in the art, thehalogen utilization efficiency (usually expressed in percentage) can beeffected by the degree of unsaturation of the starting polymer, theamount of halogen used for the reaction, and the reaction conditionssuch as temperature and residence time.

Polymers

Isobutylene-based polymers are widely used in industry as well as theirmethods of manufacture. Halogenated isobutylene base polymers are oftenthe polymer of choice for applications where air impermeability isimportant. They are generally produced using continuous or batchcationic polymerization processes employing a high concentration of aC₄-C₈ isoolefin such as isobutylene in various types of reactors such asa plug flow reactor and/or stirred tank reactors.

In an embodiment, the isobutylene-based polymer made may be polymerizedby contacting one or more monomer(s), one or more Lewis acids, and oneor more initiators in a diluent comprising one or morehydrofluorocarbon(s) (HFCs) all discussed in more detail below and, forexample, in WO 2004/058828 and WO 2004/058827.

Several of the more commercially significant isobutylene-based polymerssuch as “butyl rubbers” are available from ExxonMobil Chemical Company,Houston, Tex., and Lanxess Corporation, Pittsburgh, Pa.

Several monomers and combinations of monomers are provided below toillustrate the vast array of variations possible along with an equallydiverse array of variations possible with the catalyst system that maybe employed to produce such polymers.

Monomers

Exemplary monomers include one or more of olefins, alpha-olefins,disubstituted olefins, isoolefins, conjugated dienes, non-conjugateddienes, styrenics and/or substituted styrenics and vinyl ethers. Thestyrenic may be substituted (on the ring) with an alkyl, aryl, halide oralkoxide group. Preferably, the monomer contains 2 to 20 carbon atoms,more preferably 2 to 9, even more preferably 3 to 9 carbon atoms.Examples of preferred olefins include styrene, para-alkylstyrene,para-methylstyrene, alpha-methyl styrene, divinylbenzene,diisopropenylbenzene, isobutylene, 2-methyl-1-butene, 3-methyl-1-butene,2-methyl-2-pentene, isoprene, butadiene, 2,3-dimethyl-1,3-butadiene,β-pinene, myrcene, 6,6-dimethyl-fulvene, hexadiene, cyclopentadiene,piperylene, methyl vinyl ether, ethyl vinyl ether, and isobutyl vinylether and the like. Monomer may also be combinations of two or moremonomers. Styrenic block copolymers may also be used a monomers.Preferred block copolymers include copolymers of styrenics, such asstyrene, para-methylstyrene, alpha-methylstyrene, and C₄ to C₃₀diolefins, such as isoprene, butadiene, and the like. Particularlypreferred monomer combinations include 1) isobutylene and para-methylstyrene 2) isobutylene and isoprene, as well as homopolymers ofisobutylene.

Additionally, preferred monomers include those that are cationicallypolymerizable as described in Cationic Polymerization of Olefins, ACritical Inventory, Joseph Kennedy, Wiley Interscience, New York 1975.Monomers include any monomer that is cationically polymerizable, such asthose monomers that are capable of stabilizing a cation or propagatingcenter because the monomer contains an electron donating group. For adetailed discussion of cationic catalysis see Cationic Polymerization ofOlefins, A Critical Inventory, Joseph Kennedy, Wiley Interscience, NewYork 1975.

The monomers may be present in the polymerization medium in an amountranging from 75 wt % to 0.01 wt % in one embodiment, alternatively 60 wt% to 0.1 wt %, alternatively from 40 wt % to 0.2 wt %, alternatively 30to 0.5 wt %, alternatively 20 wt % to 0.8 wt %, alternatively and from15 wt % to 1 wt % in another embodiment.

Preferred polymers include homopolymers of any of the monomers listed inthis Section. Examples of homopolymers include polyisobutylene,polypara-methylstyrene, polyisoprene, polystyrene,polyalpha-methylstyrene, polyvinyl ethers (such as polymethylvinylether,polyethylvinylether).

Preferred polymers also include copolymers of 1) isobutylene and analkylstyrene such as methylstyrene, preferably para-methylstyrene; and2) isobutylene and isoprene.

In one embodiment butyl polymers may be prepared by reacting a comonomermixture, the mixture having at least (1) a C₄ to C₆ isoolefin monomercomponent such as isobutene with (2) a multiolefin, or conjugated dienemonomer component. The isoolefin is in a range from 70 to 99.5 wt % byweight of the total comonomer mixture in one embodiment, 85 to 99.5 wt %in another embodiment. In yet another embodiment the isoolefin is in therange of 92 to 99.5 wt %. The conjugated diene component in oneembodiment is present in the comonomer mixture from 30 to 0.5 wt % inone embodiment, and from 15 to 0.5 wt % in another embodiment. In yetanother embodiment, from 8 to 0.5 wt % of the comonomer mixture isconjugated diene. The C₄ to C₆ isoolefin may be one or more ofisobutene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, and4-methyl-1-pentene. The multiolefin may be a C₄ to C₁₄ conjugated dienesuch as isoprene, butadiene, 2,3-dimethyl-1,3-butadiene, β-pinene,myrcene, 6,6-dimethyl-fulvene, hexadiene, cyclopentadiene andpiperylene. One embodiment of the butyl rubber polymer of the inventionis obtained by reacting 85 to 99.5 wt % of isobutylene with 15 to 0.5 wt% isoprene, or by reacting 95 to 99.5 wt % isobutylene with 5.0 wt % to0.5 wt % isoprene in yet another embodiment. The following tableillustrates how the above-referenced wt % would be expressed as mol %.

wt % IC4^(a) mol % IC4 wt % IC5^(b) Mol % IC5 70 73.9 .5 .4 85 87.3 54.2 92 93.3 8 6.7 95 95.9 15 12.7 99.5 99.6 30 26.1 ^(a)IC4 -isobutylene ^(b)IC5 - isoprene

This invention further relates to terpolymers and tetrapolymerscomprising any combination of the monomers listed above. Preferredterpolymers and tetrapolymers include polymers comprising isobutylene,isoprene and divinylbenzene, polymers comprising isobutylene,para-alkylstyrene (preferably paramethyl styrene) and isoprene, polymerscomprising cyclopentadiene, isobutylene, and paraalkyl styrene(preferably paramethyl styrene), polymers of isobutylene cyclopentadieneand isoprene, polymers comprising cyclopentadiene, isobutylene, andmethyl cyclopentadiene, polymers comprising isobutylene,paramethylstyrene and cyclopentadiene.

Catalyst System

The catalyst system generally includes at least one Lewis Acid and atleast one Initiator. The Lewis acid (also referred to as theco-initiator or catalyst) may be any Lewis acid based on metals fromGroup 4, 5, 13, 14 and 15 of the Periodic Table of the Elements,including boron, aluminum, gallium, indium, titanium, zirconium, tin,vanadium, arsenic, antimony, and bismuth. One skilled in the art willrecognize that some elements are better suited in the practice of theinvention. In one embodiment, the metals are aluminum, boron andtitanium, with aluminum being desirable. Illustrative examples includeAlCl₃, (alkyl)AlCl₂, (C₂H₅)₂AlCl and (C₂H₅)₃Al₂Cl₃, BF₃, SnCl₄, TiCl₄.

Additionally, Lewis acids may be any of those useful in cationicpolymerization of isobutylene copolymers including: aluminumtrichloride, aluminum tribromide, ethylaluminum dichloride,ethylaluminum sesquichloride, diethylaluminum chloride, methylaluminumdichloride, methylaluminum sesquichloride, dimethylaluminum chloride,boron trifluoride, titanium tetrachloride, etc. with ethylaluminumdichloride and ethylaluminum sesquichloride being preferred.

Lewis acids such as methylaluminoxane (MAO) and specifically designedweakly coordinating Lewis acids such as B(C₆F₅)₃ are also suitable Lewisacids within the context of the invention.

As one skilled in the art will recognize the aforementioned listing ofLewis acids is not exhaustive and is provided for illustration. For amore information regarding Lewis acids in polymerization processes, see,for example, WO 2004/058828 and WO 2004/058827.

Initiators useful in this invention are those initiators which arecapable of being complexed in a suitable diluent with the chosen Lewisacid to yield a complex which rapidly reacts with the olefin therebyforming a propagating polymer chain. Illustrative examples includeBrönsted acids such as H₂O, HCl, RCOOH (wherein R is an alkyl group),and alkyl halides, such as (CH₃)₃CCl, C₆H₅C(CH₃)₂Cl and(2-Chloro-2,4,4-trimethylpentane). More recently, transition metalcomplexes, such as metallocenes and other such materials that can act assingle site catalyst systems, such as when activated with weaklycoordinating Lewis acids or Lewis acid salts have been used to initiateisobutylene polymerization.

In an embodiment, the initiator comprises one or more of a hydrogenhalide, a carboxylic acid, a carboxylic acid halide, a sulfonic acid, analcohol, a phenol, a tertiary alkyl halide, a tertiary aralkyl halide, atertiary alkyl ester, a tertiary aralkyl ester, a tertiary alkyl ether,a tertiary aralkyl ether, alkyl halide, aryl halide, alkylaryl halide,or arylalkylacid halide.

As one skilled in the art will recognize the aforementioned listing ofinitiator(s) is not exhaustive and is provided for illustration. For amore information regarding initiator(s) in polymerization processes,see, for example, WO 2004/058828 and WO 2004/058827.

Regardless of whether these polymers are obtained commercially such asin bale form, processed into smaller particles, and subsequentlydissolved by a solvent, and then subjected to a halogenation process, orby an continuous process incorporating the polymerization process stagefollowed by a dissolving stage, and a halogenation stage, thehalogenation process may proceed accordingly.

Halogenation

In an embodiment, a halogenation process proceeds as follows. Thepolymer is dissolved in an inert hydrocarbon solvent such as pentane,hexane, or heptane and the solution is fed to a halogenation reactor.The halogenation reactor is typically a vessel equipped with inlet andoutlet lines and an agitator. A halogen such as bromine is also fed tothe halogenation reactor at a controlled rate in relation to the amountof polymer and the double bond content of the polymer. The material fromthe reactor is treated with an aqueous alkaline solution, such as sodiumhydroxide, to neutralize the hydrogen bromide formed in the halogenationreaction and to react with residual bromine and then contacted with hotwater and steam to remove the solvent and produce a slurry of brominatedpolymer in water which is then handled in a conventional manner to yieldthe essentially dry halogenated polymer.

In some embodiments, the halogenation process can be facilitated by theuse of a free radical initiator or radical initiator. A radicalinitiator may be any molecular fragment having one or more unpairedelectrons, typically relatively short-lived and highly reactive. As iswell understood, free radical initiation may occur through applicationof light (photochemically), heat (thermally), and/or a compound orsensitizer such as organic peroxide or bis azo compound. Commontechniques are disclosed, for example, in U.S. Pat. No. 5,162,445. In anembodiment, random copolymers of isobutylene and para-methylstyrene asdescribed herein may be halogenated through the use of the radicalinitiators.

Exemplary initiators are bis azo compounds such as azo bisisobutyronitrile, azo bis(2,4 dimethyl valero) nitrile, azo bis (2methyl butyro) nitrile, and the like. Other radical initiators can alsobe used, but it is preferred to use a radical initiator which isrelatively poor at hydrogen abstraction, so that it reactspreferentially with the halogen molecules such as bromine molecules toform, for example, bromine atoms rather than with the copolymer orsolvent to form alkyl radicals.

Such compounds are commercially available, for example, as VAZO™ 52initiator and VAZO™ 67 initiator.

In certain embodiments, the amount of radical initiator employed mayvary between 0.02 and 1.00% by weight of the copolymer, alternatively,between about 0.02 and 0.30%.

Regardless of whether light, heat, and/or a radical initiator isemployed, the halogenation process may proceed using a solvent or amixed solvent comprising a non-functionalized hydrocarbon such as aninert saturated paraffinic hydrocarbon such as a non-functionalizedhydrocarbon solvent and a halogen-containing hydrocarbon such as atleast one hydrofluorocarbon.

For example, the hydrocarbon may be selected from C₄ to C₂₂ linear,cyclic, branched alkanes, alkenes, aromatics, and mixtures thereof.Other examples include butane, pentane, methylcyclopentane, isohexane,2-methylpentane, 3-methylpentane, 2-methylbutane, 2,2-dimethylbutane,2,3-dimethylbutane, 2-methylhexane, 3-methylhexane, 3-ethylpentane,2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane,3,3-dimethyl pentane, 2-methylheptane, 3-ethylhexane,2,5-dimethylhexane, 2,2,4,-trimethylpentane, octane, heptane, butane,nonane, decane, dodecane, undecane, hexane, methyl cyclohexane,cyclopropane, cyclobutane, cyclopentane, methylcyclopentane,1,1-dimethylcyclopentane, c is 1,2-dimethylcyclopentane,trans-1,2-dimethylcyclopentane, trans-1,3-dimethylcyclopentane,ethylcyclopentane, cyclohexane, methylcyclohexane, and mixtures thereof.Other examples of hydrocarbons include benzene, toluene, xylene,ortho-xylene, para-xylene, meta-xylene.

And yet other examples include but are not limited to butane, pentane,methylcyclopentane, isohexane, 2-methylpentane, 3-methylpentane,2-methylbutane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methylhexane,3-methylhexane, 3-ethylpentane, 2,2-dimethylpentane,2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethyl pentane,2-methylheptane, 3-ethylhexane, 2,5-dimethylhexane,2,24,-trimethylpentane, octane, heptane, butane, nonane, decane,dodecane, undecane, hexane, methyl cyclohexane, cyclopropane,cyclobutane, cyclopentane, methylcyclopentane, 1,1-dimethylcyclopentane,c is 1,2-dimethylcyclopentane, trans-1,2-dimethylcyclopentane,trans-1,3-dimethylcyclopentane, ethylcyclopentane, cyclohexane,methylcyclohexane, benzene, toluene, xylene, ortho-xylene, para-xylene,meta-xylene, and mixtures thereof.

In an embodiment, the hydrocarbon is hexane such as cyclohexane.

The halogen-containing hydrocarbon is at least one hydrofluorocarbon.Hydrofluorocarbons (“HFCs” or “HFC”) are defined to be saturated orunsaturated compounds consisting essentially of hydrogen, carbon andfluorine, provided that at least one carbon, at least one hydrogen, andat least one fluorine are present.

In certain embodiments, the at least one hydrofluorocarbon isrepresented by the formula: C_(x)H_(y)F_(z) wherein x is an integer from1 to 40, alternatively from 1 to 30, alternatively from 1 to 20,alternatively from 1 to 10, alternatively from 1 to 6, alternativelyfrom 2 to 20 alternatively from 3 to 10, alternatively from 3 to 6, mostpreferably from 1 to 3, wherein y and z are integers and at least one.

Illustrative examples include fluoromethane; difluoromethane;trifluoromethane; fluoroethane; 1,1-difluoroethane; 1,2-difluoroethane;1,1,1-trifluoroethane; 1,1,2-trifluoroethane; 1,1,1,2-tetrafluoroethane;1,1,2,2-tetrafluoroethane; 1,1,1,2,2-pentafluoroethane; 1-fluoropropane;2-fluoropropane; 1,1-difluoropropane; 1,2-difluoropropane;1,3-difluoropropane; 2,2-difluoropropane; 1,1,1-trifluoropropane;1,1,2-trifluoropropane; 1,1,3-trifluoropropane; 1,2,2-trifluoropropane;1,2,3-trifluoropropane; 1,1,1,2-tetrafluoropropane;1,1,1,3-tetrafluoropropane; 1,1,2,2-tetrafluoropropane;1,1,2,3-tetrafluoropropane; 1,1,3,3-tetrafluoropropane;1,2,2,3-tetrafluoropropane; 1,1,1,2,2-pentafluoropropane;1,1,1,2,3-pentafluoropropane; 1,1,1,3,3-pentafluoropropane;1,1,2,2,3-pentafluoropropane; 1,1,2,3,3-pentafluoropropane;1,1,1,2,2,3-hexafluoropropane; 1,1,1,2,3,3-hexafluoropropane;1,1,1,3,3,3-hexafluoropropane; 1,1,1,2,2,3,3-heptafluoropropane;1,1,1,2,3,3,3-heptafluoropropane; 1-fluorobutane; 2-fluorobutane;1,1-difluorobutane; 1,2-difluorobutane; 1,3-difluorobutane;1,4-difluorobutane; 2,2-difluorobutane; 2,3-difluorobutane;1,1,1-trifluorobutane; 1,1,2-trifluorobutane; 1,1,3-trifluorobutane;1,1,4-trifluorobutane; 1,2,2-trifluorobutane; 1,2,3-trifluorobutane;1,3,3-trifluorobutane; 2,2,3-trifluorobutane; 1,1,1,2-tetrafluorobutane;1,1,1,3-tetrafluorobutane; 1,1,1,4-tetrafluorobutane;1,1,2,2-tetrafluorobutane; 1,1,2,3-tetrafluorobutane;1,1,2,4-tetrafluorobutane; 1,1,3,3-tetrafluorobutane;1,1,3,4-tetrafluorobutane; 1,1,4,4-tetrafluorobutane;1,2,2,3-tetrafluorobutane; 1,2,2,4-tetrafluorobutane;1,2,3,3-tetrafluorobutane; 1,2,3,4-tetrafluorobutane;2,2,3,3-tetrafluorobutane; 1,1,1,2,2-pentafluorobutane;1,1,1,2,3-pentafluorobutane; 1,1,1,2,4-pentafluorobutane;1,1,1,3,3-pentafluorobutane; 1,1,1,3,4-pentafluorobutane;1,1,1,4,4-pentafluorobutane; 1,1,2,2,3-pentafluorobutane;1,1,2,2,4-pentafluorobutane; 1,1,2,3,3-pentafluorobutane;1,1,2,4,4-pentafluorobutane; 1,1,3,3,4-pentafluorobutane;1,2,2,3,3-pentafluorobutane; 1,2,2,3,4-pentafluorobutane;1,1,1,2,2,3-hexafluorobutane; 1,1,1,2,2,4-hexafluorobutane;1,1,1,2,3,3-hexafluorobutane, 1,1,1,2,3,4-hexafluorobutane;1,1,1,2,4,4-hexafluorobutane; 1,1,1,3,3,4-hexafluorobutane;1,1,1,3,4,4-hexafluorobutane; 1,1,1,4,4,4-hexafluorobutane;1,1,2,2,3,3-hexafluorobutane; 1,1,2,2,3,4-hexafluorobutane;1,1,2,2,4,4-hexafluorobutane; 1,1,2,3,3,4-hexafluorobutane;1,1,2,3,4,4-hexafluorobutane; 1,2,2,3,3,4-hexafluorobutane;1,1,1,2,2,3,3-heptafluorobutane; 1,1,1,2,2,4,4-heptafluorobutane;1,1,1,2,2,3,4-heptafluorobutane; 1,1,1,2,3,3,4-heptafluorobutane;1,1,1,2,3,4,4-heptafluorobutane; 1,1,1,2,4,4,4-heptafluorobutane;1,1,1,3,3,4,4-heptafluorobutane; 1,1,1,2,2,3,3,4-octafluorobutane;1,1,1,2,2,3,4,4-octafluorobutane; 1,1,1,2,3,3,4,4-octafluorobutane;1,1,1,2,2,4,4,4-octafluorobutane; 1,1,1,2,3,4,4,4-octafluorobutane;1,1,1,2,2,3,3,4,4-nonafluorobutane; 1,1,1,2,2,3,4,4,4-nonafluorobutane;1-fluoro-2-methylpropane; 1,1-difluoro-2-methylpropane;1,3-difluoro-2-methylpropane; 1,1,1-trifluoro-2-methylpropane;1,1,3-trifluoro-2-methylpropane; 1,3-difluoro-2-(fluoromethyl)propane;1,1,1,3-tetrafluoro-2-methylpropane;1,1,3,3-tetrafluoro-2-methylpropane;1,1,3-trifluoro-2-(fluoromethyl)propane;1,1,1,3,3-pentafluoro-2-methylpropane;1,1,3,3-tetrafluoro-2-(fluoromethyl)propane;1,1,1,3-tetrafluoro-2-(fluoromethyl)propane; fluorocyclobutane;1,1-difluorocyclobutane; 1,2-difluorocyclobutane;1,3-difluorocyclobutane; 1,1,2-trifluorocyclobutane;1,1,3-trifluorocyclobutane; 1,2,3-trifluorocyclobutane;1,1,2,2-tetrafluorocyclobutane; 1,1,3,3-tetrafluorocyclobutane;1,1,2,2,3-pentafluorocyclobutane; 1,1,2,3,3-pentafluorocyclobutane;1,1,2,2,3,3-hexafluorocyclobutane; 1,1,2,2,3,4-hexafluorocyclobutane;1,1,2,3,3,4-hexafluorocyclobutane; 1,1,2,2,3,3,4-heptafluorocyclobutane;and mixtures thereof and including mixtures of unsaturated HFC'sdescribed below. Particularly preferred HFC's include difluoromethane,trifluoromethane, 1,1-difluoroethane, 1,1,1-trifluoroethane,fluoromethane, and 1,1,1,2-tetrafluoroethane.

Illustrative examples of unsaturated hydrofluorocarbons include vinylfluoride; 1,1-difluoroethane; 1,2-difluoroethane; 1,1,2-trifluoroethene;1-fluoropropene, 1,1-difluoropropene; 1,2-difluoropropene;1,3-difluoropropene; 2,3-difluoropropene; 3,3-difluoropropene;1,1,2-trifluoropropene; 1,1,3-trifluoropropene; 1,2,3-trifluoropropene;1,3,3-trifluoropropene; 2,3,3-trifluoropropene; 3,3,3-trifluoropropene;1-fluoro-1-butene; 2-fluoro-1-butene; 3-fluoro-1-butene;4-fluoro-1-butene; 1,1-difluoro-1-butene; 1,2-difluoro-1-butene;1,3-difluoropropene; 1,4-difluoro-1-butene; 2,3-difluoro-1-butene;2,4-difluoro-1-butene; 3,3-difluoro-1-butene; 3,4-difluoro-1-butene;4,4-difluoro-1-butene; 1,1,2-trifluoro-1-butene;1,1,3-trifluoro-1-butene; 1,1,4-trifluoro-1-butene;1,2,3-trifluoro-1-butene; 1,2,4-trifluoro-1-butene;1,3,3-trifluoro-1-butene; 1,3,4-trifluoro-1-butene;1,4,4-trifluoro-1-butene; 2,3,3-trifluoro-1-butene;2,3,4-trifluoro-1-butene; 2,4,4-trifluoro-1-butene;3,3,4-trifluoro-1-butene; 3,4,4-trifluoro-1-butene;4,4,4-trifluoro-1-butene; 1,1,2,3-tetrafluoro-1-butene;1,1,2,4-tetrafluoro-1-butene; 1,1,3,3-tetrafluoro-1-butene;1,1,3,4-tetrafluoro-1-butene; 1,1,4,4-tetrafluoro-1-butene;1,2,3,3-tetrafluoro-1-butene; 1,2,3,4-tetrafluoro-1-butene;1,2,4,4-tetrafluoro-1-butene; 1,3,3,4-tetrafluoro-1-butene;1,3,4,4-tetrafluoro-1-butene; 1,4,4,4-tetrafluoro-1-butene;2,3,3,4-tetrafluoro-1-butene; 2,3,4,4-tetrafluoro-1-butene;2,4,4,4-tetrafluoro-1-butene; 3,3,4,4-tetrafluoro-1-butene;3,4,4,4-tetrafluoro-1-butene; 1,1,2,3,3-pentafluoro-1-butene;1,1,2,3,4-pentafluoro-1-butene; 1,1,2,4,4-pentafluoro-1-butene;1,1,3,3,4-pentafluoro-1-butene; 1,1,3,4,4-pentafluoro-1-butene;1,1,4,4,4-pentafluoro-1-butene; 1,2,3,3,4-pentafluoro-1-butene;1,2,3,4,4-pentafluoro-1-butene; 1,2,4,4,4-pentafluoro-1-butene;2,3,3,4,4-pentafluoro-1-butene; 2,3,4,4,4-pentafluoro-1-butene;3,3,4,4,4-pentafluoro-1-butene; 1,1,2,3,3,4-hexafluoro-1-butene;1,1,2,3,4,4-hexafluoro-1-butene; 1,1,2,4,4,4-hexafluoro-1-butene;1,2,3,3,4,4-hexafluoro-1-butene; 1,2,3,4,4,4-hexafluoro-1-butene;2,3,3,4,4,4-hexafluoro-1-butene; 1,1,2,3,3,4,4-heptafluoro-1-butene;1,1,2,3,4,4,4-heptafluoro-1-butene; 1,1,3,3,4,4,4-heptafluoro-1-butene;1,2,3,3,4,4,4-heptafluoro-1-butene; 1-fluoro-2-butene;2-fluoro-2-butene; 1,1-difluoro-2-butene; 1,2-difluoro-2-butene;1,3-difluoro-2-butene; 1,4-difluoro-2-butene; 2,3-difluoro-2-butene;1,1,1-trifluoro-2-butene; 1,1,2-trifluoro-2-butene;1,1,3-trifluoro-2-butene; 1,1,4-trifluoro-2-butene;1,2,3-trifluoro-2-butene; 1,2,4-trifluoro-2-butene;1,1,1,2-tetrafluoro-2-butene; 1,1,1,3-tetrafluoro-2-butene;1,1,1,4-tetrafluoro-2-butene; 1,1,2,3-tetrafluoro-2-butene;1,1,2,4-tetrafluoro-2-butene; 1,2,3,4-tetrafluoro-2-butene;1,1,1,2,3-pentafluoro-2-butene; 1,1,1,2,4-pentafluoro-2-butene;1,1,1,3,4-pentafluoro-2-butene; 1,1,1,4,4-pentafluoro-2-butene;1,1,2,3,4-pentafluoro-2-butene; 1,1,2,4,4-pentafluoro-2-butene;1,1,1,2,3,4-hexafluoro-2-butene; 1,1,1,2,4,4-hexafluoro-2-butene;1,1,1,3,4,4-hexafluoro-2-butene; 1,1,1,4,4,4-hexafluoro-2-butene;1,1,2,3,4,4-hexafluoro-2-butene; 1,1,1,2,3,4,4-heptafluoro-2-butene;1,1,1,2,4,4,4-heptafluoro-2-butene; and mixtures thereof and includingmixtures of saturated HFC's described above.

In another embodiment the HFC is selected from the group consisting ofdifluoromethane, trifluoromethane, 1,1-difluoroethane,1,1,1-trifluoroethane, and 1,1,1,2-tetrafluoroethane, and mixturesthereof.

In certain embodiments, the at least one hydrofluorocarbon has adielectric constant of greater than 10 at −85° C., preferably greaterthan 15, more preferably greater than 20, more preferably greater than25, more preferably 40 or more. The dielectric constant ∈_(D) isdetermined from measurements of the capacitance of a parallel-platecapacitor immersed in a fluid [measured value C_(D)], in a referencefluid of known dielectric constant ∈_(R) [measured value C_(R)], and inair (∈_(A)=1) [measured value C_(A)]. In each case the measuredcapacitance C_(M) is given by C_(M)=∈C_(C)+C_(S), where ∈ is thedielectric constant of the fluid in which the capacitor is immersed,C_(C) is the cell capacitance, and C_(S) is the stray capacitance. Fromthese measurements ∈_(D) is given by the formula∈_(D)=((C_(D)−C_(A))∈_(R)+(C_(R)−C_(D)))/(C_(R)−C_(A)). Alternatively, apurpose-built instrument such as the Brookhaven Instrument CorporationBIC-870 may be used to measure dielectric constant of a fluid. Acomparison of the dielectric constants (∈) of a few fluids at −85° C. isprovided below.

Fluid ε at −85° C. Methyl chloride 18.34 Difluoromethane 36.291,1-difluoroethane 29.33 1,1,1-trifluoroethane 22.181,1,1,2-tetrafluoroethane 23.25 1,1,2,2-tetrafluoroethane 11.271,1,1,2,2-pentafluoroethane 11.83

In certain embodiments, the HFC is typically present at 1 to 50 volume %based upon the total volume of the solution, alternatively between 5 and50 volume %, alternatively between 10 and 50 volume %, alternativelybetween 15 and 50 volume %, alternatively between 20 and 50 volume %,and alternatively between 25 and 50 volume %, These ranges may vary;however, as would be expected, the maximum amount of an HFC in asolution is limited by the solubility of polymer in the solution.

In yet other embodiments, the volume ratio of the hydrocarbon tohydrofluorocarbon is from about 90 parts to 10 parts to about 50 partsto 50 parts.

The solution in which the polymer is halogenated may also contain up toabout 20, alternatively, from about 1 to about 15, volume percent ofwater based on the total solution.

Thus, in certain embodiments, using such a mixture as solvent for thepolymer leads to an increase in the amount of halogen such as brominewhich is incorporated into the polymer to form chemical structures thathelp facilitate the vulcanization of the polymer.

INDUSTRIAL APPLICATIONS

The invention described herein may be used to manufacture halogenatedpolymers useful in wide variety of applications. The low degree ofpermeability to gases accounts for the largest uses of these polymers,namely inner tubes and tire innerliners. These same properties are alsoof importance in air cushions, pneumatic springs, air bellows,accumulator bags, and pharmaceutical closures. The thermal stability ofthe polymers of the invention make them ideal for rubber tire-curingbladders, high temperature service hoses, and conveyor belts for hotmaterial handling.

In certain embodiments, the halogenated polymers exhibit high dampingand have uniquely broad damping and shock absorption ranges in bothtemperature and frequency. They are useful in molded rubber parts andfind wide applications in automobile suspension bumpers, auto exhausthangers, and body mounts.

In yet other embodiments, the halogenated polymers of the instantinvention are useful in tire sidewalls and tread compounds. Insidewalls, the polymer characteristics impart good ozone resistance,crack cut growth, and appearance. The polymers of the invention may alsobe blended. Properly formulated blends with high diene rubbers thatexhibit phase co-continuity yield excellent sidewalls. Improvements inwet, snow, and ice skid resistances and in dry traction withoutcompromises in abrasion resistance and rolling resistance for highperformance tires can be accomplished by using the polymers of theinstant invention.

The halogenated polymers may also be used as adhesives, caulks,sealants, and glazing compounds. In certain applications, thehalogenated polymers are useful in medical applications such aspharmaceutical stoppers, and the arts for paint rollers.

The following examples reflect embodiments of the invention and are byno means intended to be limiting of the scope of the invention.

EXAMPLES Bromination of Polymer in a Hydrocarbon Solution

Bromination of a butyl polymer made in 1,1,1,2-tetrafluoroethane(R-134a) as well as the comparative butyl polymer made in methylchloride (MeCl) was carried out using typical batch brominationtechnique. Prior to the bromination step, butyl polymer solution(cement) was prepared by dissolving desirable amount of butyl polymersample in proper amount of cyclohexane (Aldrich, 99.9+, HPCL grade, lot#CA 00148CA) in a 500 ml round bottom flask. Bromine solutions wereprepared by diluting liquid bromine (Aldrich Chemical Co., 99.5%, A.C.S.reagent grade, lot #10020 HR) with 3-5 times volume of cyclohexane inorder to improve dispersion of bromine molecules in polymer solution.

Bromination reaction was carried out by adding the above brominesolution into the polymer solution with vigorous agitation. A standard3-neck round bottom flask was utilized as the bromination reactor. Lightexposure was carefully minimized during the bromination reaction inorder to avoid/minimize the formation of bromine radicals. The brominesolution (based on the bromine target, the weight of polymer in thereactor, and the expected bromine utilization under the experimentalconditions) was added slowly to the reactor using an addition funnel.The bromination reaction was allowed to continue for an additionalminute. After the bromine addition was complete, the reaction mixturewas quenched with 2 wt % aqueous solution of sodium hydroxide (Fishercertified, 99.9%, A.C.S. grade) in de-ionized water to form a quenchedpolymer solution. The quenched polymer solution was vigorously stirredfor 15 to 20 minutes to make sure all residual bromine and brominationby-product (HBr) were completely neutralized. The neutralized polymersolution was allowed to settle until an aqueous bottom layer was clearlyseparated from top organic polymer solution.

The above brominated, neutralized polymer solution mixture was decantedinto a large separatory funnel and washed with de-ionized water severaltimes until the pH of the aqueous phase is neutral. The bottom aqueouslayer was drained leaving the polymer solution behind. The polymersolution was transferred to a large beaker a 3-liter beaker and polymerwas precipitated out of solution by slowly adding methanol (Fishercertified A.C.S. grade, 99.9%) to the polymer solution with continuousstirring. The precipitated polymer (99+% yield) was dried in a vacuumoven at 35° C. with nitrogen purge for several days before submitted forproton NMR analysis.

The mole % of Structure II (bromine incorporated at a secondary allylicposition) and Structure III (bromine incorporated at a primary allylicposition) isomers in the brominated polymers were determined by standardproton NMR analysis using a 500 MHz Varian Unity Plus NMR spectrometerin either CDCl₃ or toluene-d₈ at ambient temperature. The total mole %Br is the sum of Structure II and Structure III isomers and the total wt% Br were calculated from total mole % Br.

Isoprene Content of Starting Br2 Total Total Polymer Polymer addedStructure Structure Br Br Sample (starting backbone) (Mole %) wt. (g)(g) II (m %) III (m %) (m %) (wt %) A (Butyl from R-134a) 1.54 67.372.06 0.146 0.912 1.06 1.51 B (Butyl from R-134a) 1.54 68.04 1.70 0.1370.910 1.05 1.50 C (Butyl from R-134a) 1.54 69.94 2.14 0.156 0.895 1.051.50 D (Butyl from MeCl) 1.66 68.08 1.88 0.151 0.955 1.11 1.58 E (Butylfrom MeCl) 1.66 62.70 2.01 0.144 0.956 1.10 1.57 F (Butyl from MeCl)1.66 54.62 1.63 0.200 0.918 1.12 1.60 G (Butyl 2255 backbone) 0.96 15.001.50 0.177 0.996 1.173 1.68 H (Butyl from R-134a) 1.54 100.02 6.70 0.2680.736 1.004 1.44 I (Butyl from R-134a) 1.54 100.01 6.71 0.346 0.6741.020 1.46 J (Butyl from MeCl) 1.66 100.02 6.71 0.209 0.682 0.891 1.27 K(Butyl from MeCl) 1.66 100.00 6.70 0.220 0.659 0.879 1.26

The data indicated that the butyl polymer made in the presence R-134ashowed similar performance or higher bromination utilization than thebutyl polymer made in MeCl using similar bromination conditions.Additionally, either result represents an improvement over traditionalpolymers made in methyl chloride which were then halogenated because theinventive examples demonstrate the compatibility and feasibility of acontinuous polymerization process including one or more HFCs followed byinventive halogenation processes.

Bromination of Polymer Using a Mixed Solvent

Bromination of butyl polymers was carried out using typical batchbromination technique. Prior to the bromination step, various amounts of1,1,1,2-tetrafluoroethane (HFC R-134a DuPont, commercial grade, >98%purity) or 1,1,1,3,3,-pentafluoropropane (HFC 365, Honeywell, commercialgrade, >98% purity), were added to Butyl 268 polymer (a commercial gradebutyl rubber from ExxonMobil Chemical Company, Houston, Tex.) in hexane(ULB, technical grade) solution (cement) containing 6 wt % butyl polymerin a 500 ml round bottom flask. The addition of R-134a HFC to polymercement was carried out by bubbling R-134a gas through the butyl polymercement for 10 minutes to reach saturation at room temperature. HFC-365was added to butyl polymer cement as liquid with agitation. Brominesolutions were prepared by diluting liquid bromine (Aldrich ChemicalCo., 99.5%, A.C.S. reagent grade, lot #10020 HR) with 3-5 times volumeof cyclohexane in order to improve dispersion of bromine molecules inpolymer solution.

Bromination reaction was carried out by adding above bromine solutioninto the polymer solution with vigorous agitation. Light exposure wascarefully minimized during bromination reaction in order toavoid/minimize the formation of bromine radicals. The bromine solution(based on the bromine target, the weight of polymer in the reactor andthe expected bromine utilization under the experimental conditions) wasadded slowly to the reactor using an addition funnel. The brominationreaction was allowed to continue for additional minute after the bromineaddition was complete and then the reaction mixture was quenched with 2wt % aqueous solution of sodium hydroxide (Fisher certified, 99.9%,A.C.S. grade) in de-ionized water. The quenched polymer solution wasvigorously stirred for 15 to 20 minutes to make sure all residualbromine and bromination by-product (HBr) were completely neutralized.The neutralized polymer solution was allowed to settle until an aqueousbottom layer was clearly separated from top organic polymer solution.

The above brominated, neutralized polymer solution mixture was decantedinto a large separatory funnel and washed with de-ionized water severaltimes until the pH of the aqueous phase is neutral. The bottom aqueouslayer was drained leaving the polymer solution behind. The polymersolution was transferred to a large beaker and polymer was precipitatedout of solution by slowly adding methanol (Fisher certified A.C.S.grade, 99.9%) to the polymer solution with continuous stirring. Theprecipitated polymer (99+% yield) was dried in a vacuum oven at 35° C.with nitrogen purge for several days before submitted for proton NMRanalysis.

Proton NMR spectroscopic analyses were run in either CDCl₃ or toluene-d₈at ambient temperature using a Varian Unity Plus NMR spectrometer with afield strength of 500 MHz. Bromine can be incorporated in the isopreneunits in the polymer either as structure II (bromine incorporated at asecondary allylic position) or structure III (bromine incorporated at aprimary allylic position). The mole % of structure II and structure IIIon polymer were determined by comparing the integration of the NMRsignal of the structure II or structure III relative to the total NMRsignal of isobutylene and isoprene in the backbone polymer. The total Brwas the sum of structure II and structure III in the sample.

Relative bromination efficiency in the presence of HFC can be determinedby the relative Bromine Utilization (B.U.) which was defined as thetotal bromine incorporated onto polymer as a percentage (%) of the totalbromine added to the reactor under similar conditions. The theoreticalmaximum bromine utilization is 50% because only one Br atom from Br2molecules can be added to polymer while the other Br atom was convertedto HBr as the by-product of the bromination process. As would beexpected by an artisan, due to the difficulty of handling very viscouspolymer cement in the laboratory, the polymer concentration in thecement used in the examples was significantly lower than typical polymercontent in the cement used in commercial bromination process.Consequently, without being bound to theory, it is believed that thebromine utilization in the examples was significantly lower than whatwould be in a commercial process. Nonetheless, the principle that therelative bromine utilization in the presence versus in the absence ofHFC should have universal application regardless of scale and the datademonstrates of the positive impact of HFC addition on bromineutilization.

Br2 Total Total Polymer added Structure Structure Br Br B.U. Sample wt(g) (g) II (m %) III (m %) (m %) (wt %) (%) Butyl Cement w/o HFC 50.12.86 0.751 0.137 0.888 1.27 22.2 Butyl Cement + R-134a 50.0 2.86 0.7910.180 0.971 1.39 24.3 Butyl Cement w/1 vol % 50.0 2.86 0.830 0.116 0.9461.35 23.7 HFC-365 Butyl Cement w/5 vol % 50.0 2.87 0.819 0.178 0.9971.43 24.8 HFC-365 Butyl Cement w/10 vol % 50.0 2.87 0.758 0.302 1.061.52 26.4 HFC-365 Butyl Cement w/15 vol % 50.0 2.87 0.941 0.212 1.1531.65 28.7 HFC-365

In particular, the data demonstrated that the addition of HFC in butylpolymer cement improved bromination utilization or bromine incorporationinto the polymers. The first two rows data in Table 1 showed thatsaturating polymer hexane cement with R-134a at ambient temperatureincreased the bromine incorporation on polymer by about 9%, i.e., from0.888 m % to 0.971 m % under similar reaction conditions. The followingfour rows data clearly showed that adding increasing amount of HFC-365in polymer hexane cement increased the bromine incorporation on polymerunder similar bromination conditions. A 15 v % addition of HFC-365 topolymer cement, the bromine incorporation on polymer increased by almost30%, i.e., from 0.888 mole % Br to 1.153 mole % Br. Without being boundto theory, it is believed that the data indicated that the degree ofbromine utilization improvement increases with increasing amount of HFCaddition to polymer hexane cement. It further believed that the maximumamount of HFC that can be added to butyl polymer cement depends on theboiling point of the HFC and the compatibility of HFC with the polymercement. For example, when HFC's with low boiling point such as R-134a(b.p.=−48° C.) was used, only very limited HFC concentration can beexpected in polymer cement at ambient temperature. However, when an HFCwith higher boiling point, such as HFC-365, was used, a significantlyhigher level of HFC-365 can be added to polymer cement at ambienttemperature. It is believed that the maximum effective level of HFC canbe added to butyl polymer cement will be limited by the compatibility ofthe HFC with polymer hexane cement. Beyond the maximum acceptable HFClevel, the polymer will start to precipitate out of solution. ForHFC-365, the maximum acceptable level that can be added to polymercement without polymer precipitation was determined to be about 15 v %and the bromine incorporation increased steadily with increasing amountof HFC addition to the polymer cement. Such an increase represents asignificant improvement because this not only reduces the raw materialcost, but also reduces the amount of undesirable by-product producedfrom the bromination process.

All patents and patent applications, test procedures (such as ASTMmethods), and other documents cited herein are fully incorporated byreference to the extent such disclosure is not inconsistent with thisinvention and for all jurisdictions in which such incorporation ispermitted.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.

While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present invention,including all features which would be treated as equivalents thereof bythose skilled in the art to which the invention pertains.

1.-63. (canceled)
 64. A process to halogenate a polymer, the processcomprising contacting at least one polymer having C₄-C₁₀ isoolefinderived units, at least one halogen, and at least one hydrofluorocarbonin a solution to produce at least one halogenated polymer.
 65. Theprocess of claim 64, wherein the at least one halogenated polymerexhibits greater halogen utilization than a polymer halogenated in thepresence of a chlorinated hydrocarbon under similar conditions.
 66. Theprocess of claim 65, wherein the at least one halogenated polymerexhibits at least 5% greater halogen utilization than a polymerhalogenated in the presence of a chlorinated hydrocarbon under similarconditions.
 67. The process of claim 65, wherein the chlorinatedhydrocarbon is methyl chloride.
 68. The process of claim 66, wherein thechlorinated hydrocarbon is methyl chloride.
 69. The process of claim 64,wherein the at least one halogen is bromine or chlorine
 70. The processof claim 64, wherein the at least one polymer is a copolymer of anisoolefin, preferably isobutylene, and a multiolefin, preferably,isoprene.
 71. The process of claim 64, wherein the at least one polymeris a random copolymer of an isoolefin, preferably isobutylene, andmethylstyrene, preferably para-methylstyrene.
 72. The process of claim64, wherein the solution further comprises a radical initiator or isexposed to heat or light.
 73. The process of claim 70, wherein theradical initiator is an organic peroxide or a bis azo compound.
 74. Theprocess of claim 64, wherein the at least one halogenated polymercomprises about 1.4 or greater wt % halogen based upon the total weightof the at least one halogenated polymer.
 75. The process of claim 64,wherein the at least one hydrofluorocarbon is represented by theformula: C_(x)H_(y)F_(z) wherein x is an integer from 1 to 40 and y andz are integers of one or more.
 76. The process of claim 72, wherein x isfrom 1 to
 6. 77. The process of claim 64, wherein the at least onehydrofluorocarbon is independently selected from the group consisting offluoromethane; difluoromethane; trifluoromethane; fluoroethane;1,1-difluoroethane; 1,2-difluoroethane; 1,1,1-trifluoroethane;1,1,2-trifluoroethane; 1,1,1,2-tetrafluoroethane;1,1,2,2-tetrafluoroethane; 1,1,1,2,2-pentafluoroethane; 1-fluoropropane;2-fluoropropane; 1,1-difluoropropane; 1,2-difluoropropane;1,3-difluoropropane; 2,2-difluoropropane; 1,1,1-trifluoropropane;1,1,2-trifluoropropane; 1,1,3-trifluoropropane; 1,2,2-trifluoropropane;1,2,3-trifluoropropane; 1,1,1,2-tetrafluoropropane;1,1,1,3-tetrafluoropropane; 1,1,2,2-tetrafluoropropane;1,1,2,3-tetrafluoropropane; 1,1,3,3-tetrafluoropropane;1,2,2,3-tetrafluoropropane; 1,1,1,2,2-pentafluoropropane;1,1,1,2,3-pentafluoropropane; 1,1,1,3,3-pentafluoropropane;1,1,2,2,3-pentafluoropropane; 1,1,2,3,3-pentafluoropropane;1,1,1,2,2,3-hexafluoropropane; 1,1,1,2,3,3-hexafluoropropane;1,1,1,3,3,3-hexafluoropropane; 1,1,1,2,2,3,3-heptafluoropropane;1,1,1,2,3,3,3-heptafluoropropane; 1-fluorobutane; 2-fluorobutane;1,1-difluorobutane; 1,2-difluorobutane; 1,3-difluorobutane;1,4-difluorobutane; 2,2-difluorobutane; 2,3-difluorobutane;1,1,1-trifluorobutane; 1,1,2-trifluorobutane; 1,1,3-trifluorobutane;1,1,4-trifluorobutane; 1,2,2-trifluorobutane; 1,2,3-trifluorobutane;1,3,3-trifluorobutane; 2,2,3-trifluorobutane; 1,1,1,2-tetrafluorobutane;1,1,1,3-tetrafluorobutane; 1,1,1,4-tetrafluorobutane;1,1,2,2-tetrafluorobutane; 1,1,2,3-tetrafluorobutane;1,1,2,4-tetrafluorobutane; 1,1,3,3-tetrafluorobutane;1,1,3,4-tetrafluorobutane; 1,1,4,4-tetrafluorobutane;1,2,2,3-tetrafluorobutane; 1,2,2,4-tetrafluorobutane;1,2,3,3-tetrafluorobutane; 1,2,3,4-tetrafluorobutane;2,2,3,3-tetrafluorobutane; 1,1,1,2,2-pentafluorobutane;1,1,1,2,3-pentafluorobutane; 1,1,1,2,4-pentafluorobutane;1,1,1,3,3-pentafluorobutane; 1,1,1,3,4-pentafluorobutane;1,1,1,4,4-pentafluorobutane; 1,1,2,2,3-pentafluorobutane;1,1,2,2,4-pentafluorobutane; 1,1,2,3,3-pentafluorobutane;1,1,2,4,4-pentafluorobutane; 1,1,3,3,4-pentafluorobutane;1,2,2,3,3-pentafluorobutane; 1,2,2,3,4-pentafluorobutane;1,1,1,2,2,3-hexafluorobutane; 1,1,1,2,2,4-hexafluorobutane;1,1,1,2,3,3-hexafluorobutane, 1,1,1,2,3,4-hexafluorobutane;1,1,1,2,4,4-hexafluorobutane; 1,1,1,3,3,4-hexafluorobutane;1,1,1,3,4,4-hexafluorobutane; 1,1,1,4,4,4-hexafluorobutane;1,1,2,2,3,3-hexafluorobutane; 1,1,2,2,3,4-hexafluorobutane;1,1,2,2,4,4-hexafluorobutane; 1,1,2,3,3,4-hexafluorobutane;1,1,2,3,4,4-hexafluorobutane; 1,2,2,3,3,4-hexafluorobutane;1,1,1,2,2,3,3-heptafluorobutane; 1,1,1,2,2,4,4-heptafluorobutane;1,1,1,2,2,3,4-heptafluorobutane; 1,1,1,2,3,3,4-heptafluorobutane;1,1,1,2,3,4,4-heptafluorobutane; 1,1,1,2,4,4,4-heptafluorobutane;1,1,1,3,3,4,4-heptafluorobutane; 1,1,1,2,2,3,3,4-octafluorobutane;1,1,1,2,2,3,4,4-octafluorobutane; 1,1,1,2,3,3,4,4-octafluorobutane;1,1,1,2,2,4,4,4-octafluorobutane; 1,1,1,2,3,4,4,4-octafluorobutane;1,1,1,2,2,3,3,4,4-nonafluorobutane; 1,1,1,2,2,3,4,4,4-nonafluorobutane;1-fluoro-2-methylpropane; 1,1-difluoro-2-methylpropane;1,3-difluoro-2-methylpropane; 1,1,1-trifluoro-2-methylpropane;1,1,3-trifluoro-2-methylpropane; 1,3-difluoro-2-(fluoromethyl)propane;1,1,1,3-tetrafluoro-2-methylpropane;1,1,3,3-tetrafluoro-2-methylpropane;1,1,3-trifluoro-2-(fluoromethyl)propane;1,1,1,3,3-pentafluoro-2-methylpropane;1,1,3,3-tetrafluoro-2-(fluoromethyl)propane;1,1,1,3-tetrafluoro-2-(fluoromethyl)propane; fluorocyclobutane;1,1-difluorocyclobutane; 1,2-difluorocyclobutane;1,3-difluorocyclobutane; 1,1,2-trifluorocyclobutane;1,1,3-trifluorocyclobutane; 1,2,3-trifluorocyclobutane;1,1,2,2-tetrafluorocyclobutane; 1,1,3,3-tetrafluorocyclobutane;1,1,2,2,3-pentafluorocyclobutane; 1,1,2,3,3-pentafluorocyclobutane;1,1,2,2,3,3-hexafluorocyclobutane; 1,1,2,2,3,4-hexafluorocyclobutane;1,1,2,3,3,4-hexafluorocyclobutane; 1,1,2,2,3,3,4-heptafluorocyclobutane;vinyl fluoride; 1,1-difluoroethane; 1,2-difluoroethane;1,1,2-trifluoroethene; 1-fluoropropene, 1,1-difluoropropene;1,2-difluoropropene; 1,3-difluoropropene; 2,3-difluoropropene;3,3-difluoropropene; 1,1,2-trifluoropropene; 1,1,3-trifluoropropene;1,2,3-trifluoropropene; 1,3,3-trifluoropropene; 2,3,3-trifluoropropene;3,3,3-trifluoropropene; 1-fluoro-1-butene; 2-fluoro-1-butene;3-fluoro-1-butene; 4-fluoro-1-butene; 1,1-difluoro-1-butene;1,2-difluoro-1-butene; 1,3-difluoropropene; 1,4-difluoro-1-butene;2,3-difluoro-1-butene; 2,4-difluoro-1-butene; 3,3-difluoro-1-butene;3,4-difluoro-1-butene; 4,4-difluoro-1-butene; 1,1,2-trifluoro-1-butene;1,1,3-trifluoro-1-butene; 1,1,4-trifluoro-1-butene;1,2,3-trifluoro-1-butene; 1,2,4-trifluoro-1-butene;1,3,3-trifluoro-1-butene; 1,3,4-trifluoro-1-butene;1,4,4-trifluoro-1-butene; 2,3,3-trifluoro-1-butene;2,3,4-trifluoro-1-butene; 2,4,4-trifluoro-1-butene;3,3,4-trifluoro-1-butene; 3,4,4-trifluoro-1-butene;4,4,4-trifluoro-1-butene; 1,1,2,3-tetrafluoro-1-butene;1,1,2,4-tetrafluoro-1-butene; 1,1,3,3-tetrafluoro-1-butene;1,1,3,4-tetrafluoro-1-butene; 1,1,4,4-tetrafluoro-1-butene;1,2,3,3-tetrafluoro-1-butene; 1,2,3,4-tetrafluoro-1-butene;1,2,4,4-tetrafluoro-1-butene; 1,3,3,4-tetrafluoro-1-butene;1,3,4,4-tetrafluoro-1-butene; 1,4,4,4-tetrafluoro-1-butene;2,3,3,4-tetrafluoro-1-butene; 2,3,4,4-tetrafluoro-1-butene;2,4,4,4-tetrafluoro-1-butene; 3,3,4,4-tetrafluoro-1-butene;3,4,4,4-tetrafluoro-1-butene; 1,1,2,3,3-pentafluoro-1-butene;1,1,2,3,4-pentafluoro-1-butene; 1,1,2,4,4-pentafluoro-1-butene;1,1,3,3,4-pentafluoro-1-butene; 1,1,3,4,4-pentafluoro-1-butene;1,1,4,4,4-pentafluoro-1-butene; 1,2,3,3,4-pentafluoro-1-butene;1,2,3,4,4-pentafluoro-1-butene; 1,2,4,4,4-pentafluoro-1-butene;2,3,3,4,4-pentafluoro-1-butene; 2,3,4,4,4-pentafluoro-1-butene;3,3,4,4,4-pentafluoro-1-butene; 1,1,2,3,3,4-hexafluoro-1-butene;1,1,2,3,4,4-hexafluoro-1-butene; 1,1,2,4,4,4-hexafluoro-1-butene;1,2,3,3,4,4-hexafluoro-1-butene; 1,2,3,4,4,4-hexafluoro-1-butene;2,3,3,4,4,4-hexafluoro-1-butene; 1,1,2,3,3,4,4-heptafluoro-1-butene;1,1,2,3,4,4,4-heptafluoro-1-butene; 1,1,3,3,4,4,4-heptafluoro-1-butene;1,2,3,3,4,4,4-heptafluoro-1-butene; 1-fluoro-2-butene;2-fluoro-2-butene; 1,1-difluoro-2-butene; 1,2-difluoro-2-butene;1,3-difluoro-2-butene; 1,4-difluoro-2-butene; 2,3-difluoro-2-butene;1,1,1-trifluoro-2-butene; 1,1,2-trifluoro-2-butene;1,1,3-trifluoro-2-butene; 1,1,4-trifluoro-2-butene;1,2,3-trifluoro-2-butene; 1,2,4-trifluoro-2-butene;1,1,1,2-tetrafluoro-2-butene; 1,1,1,3-tetrafluoro-2-butene;1,1,1,4-tetrafluoro-2-butene; 1,1,2,3-tetrafluoro-2-butene;1,1,2,4-tetrafluoro-2-butene; 1,2,3,4-tetrafluoro-2-butene;1,1,1,2,3-pentafluoro-2-butene; 1,1,1,2,4-pentafluoro-2-butene;1,1,1,3,4-pentafluoro-2-butene; 1,1,1,4,4-pentafluoro-2-butene;1,1,2,3,4-pentafluoro-2-butene; 1,1,2,4,4-pentafluoro-2-butene;1,1,1,2,3,4-hexafluoro-2-butene; 1,1,1,2,4,4-hexafluoro-2-butene;1,1,1,3,4,4-hexafluoro-2-butene; 1,1,1,4,4,4-hexafluoro-2-butene;1,1,2,3,4,4-hexafluoro-2-butene; 1,1,1,2,3,4,4-heptafluoro-2-butene;1,1,1,2,4,4,4-heptafluoro-2-butene; and mixtures thereof.
 78. Theprocess of claim 64, wherein the solution comprises from about 1 toabout 70 volume % of the at least one hydrofluorocarbon based upon thetotal volume of the solution.
 79. The process of claim 64, wherein thesolution comprises at least one non-halogenated hydrocarbon solvent. 80.The process of claim 64, wherein the at least one hydrofluorocarbon hasa dielectric constant (∈) of at least 19.00 at −85° C. or greater. 81.The process of claim 64, wherein the at least one polymer is producedfrom a slurry polymerization process.
 82. A process to produce ahalogenated polymer, the process comprising: 1) a slurry polymerizationprocess stage, the slurry polymerization process stage utilizing adiluent comprising at least one hydrofluorocarbon, in fluidcommunication with 2) the halogenation process of claim 64 to producethe at least one halogenated polymer.